Why don't trucks go 55 for fuel efficiency?

That boss is a slavedriver, you should unionize your workplace for better working conditions

(Yes i know, thats the joke)

 

We would definitely get the best fuel mileage if we grabbed that mule & buggy. I love the mule to much so I'll give you the buggy let you ride with it unlimited & wide open.

 

If a 10 truck fleet runs 25,000 miles per week with a speed limiter at 70 mph. Then, at 55 they would turn 20,833 miles instead.

9 mpg vs 7.5 mpg is $1665 per week in savings at $3 per gallon.

Let’s say that these trucks are averaging 2.50 per mile in revenue. And run 4166 less miles for the week. That is $10,416 dollars in lost revenue. So our savings of $1665 are negated in a big way.

So, the best is to find a good middle ground like 70 mph and a fuel efficient truck that you can still do 7.5 mpg.

Good luck with your book report. lol.

Edit: I realized my numbers are off. The savings are actually $3058 due to running less miles but still nowhere near $10,416 in lost revenue. Fuel would have to go to $10/gal for it to start to even out but rates per mile would also shoot up much higher so the savings would not keep up on a sliding scale if that makes sense.

 

I run west mostly, I generally run 70 mph and my truck is geared for a happy medium pulling power and fuel economy
Generally average 7 or so mpg. I like others could really give 2 ####s about fuel economy. I run slow because it is easier on the equipment. If mty or light Or have time I will chill in the right lane snd watch the scenery roll by if not I have places to go and freight to haul.
We’re not in Europe either. Although Commiefornia is close enough

 

Took the words right out of my mouth. There are things that have a bigger impact on the bottom line than a couple hundred extra per month in fuel costs.

And for those of you who whine about the 55 mph in California, I keep my cruise control set at 62 and get ignored by CHP every day except when I'm in construction zones. Oregon and Washington have a 60mph speed limit for trucks, but they're less forgiving than California. I usually go no faster than 62 or 63 in either of those states. If I'm heading east to Denver or SLC, I'll keep the hammer down at the speed limit and get to my truck stop of choice to relax and get a good spot a couple hours earlier than the guys going 60.

 

That's true if we're only talking about driveline efficiency (and only in direct drive trannys,) but that means ignoring the actual duty cycle on the vehicle. In some segments, aero drag plays a much greater part on the hp requirements, and slowing and running in a lower gear can reduce the hp requirements more than enough to offset any driveline losses.

Fuel economy sucks at very low throttle settings on gas engines. All that intake vacuum. It's why modern cars are geared so tall, they want the throttle butterflies as far open as possible, even under low power demands, to reduce those internal losses.

 

Ya but the other thing is the way a lot of freight is scheduled, people can't always do anything with those extra miles. Theres a lot of times when it really doesnt matter whether you drive 600 miles in 11 hours or only in 10, because you still can't deliver until 8am tomorrow regardless.

 

Thats true sometimes, and many times it’s not. This is all in theory anyway. There are so many kinds of different trucking that it’s all skewed. So I think it’s nicer to use hard numbers.

There certainly is not enough cases of what you are talking about to make up the split between the numbers I posted. Not to mention I truly believe all trucks doing 55 would be a menace to safety. I sure as heck know the public doesn’t have the patience to drop to 60 in their 4 wheelers. Many people do 80 around here and cops don’t bother them.

 

But what is 810 miles?

 

Those times, I mosey. Take it easy in the slow lane, reset when I feel like it, etc. It's nice.

Then there's times when GPS says it's a 23hr journey, and I'm like "I bet I can shave an hour off that and make it in two days with some luck." Then it's balls to the wall.